Transposition

The
transpose
and
addtranspose
parameters
can be used to transpose the pitches for a staff or the whole score.
The following table shows what transposition values to use for different
intervals.

halfsteps

transposition

alternate transposition

0

perfect 1

diminished 2

1

augmented 1

minor 2

2

major 2

diminished 3

3

augmented 2

minor 3

4

major 3

diminished 4

5

augmented 3

perfect 4

6

augmented 4

diminished 5

7

perfect 5

diminished 6

8

augmented 5

minor 6

9

major 6

diminished 7

10

augmented 6

minor 7

11

major 7

diminished 8

This table continues in a similar way for intervals beyond an octave.
For each number of halfsteps you want to transpose, there
is more than one way the
transpose
and
addtranspose
parameters can be
specified, as shown by this table. This allows to you control
whether a sharp key or a flat key is to be used in cases where there is
a choice. For example, if the key signature has three sharps, and you
want to transpose up two halfsteps, you could say either

transpose = up maj 2

or

transpose = up dim 3

The first will result in a key of five sharps, and the second will
result in seven flats. These are equivalent keys; in major for
example, they are B and C flat, which are the same note. It is up to
you to choose the way you would like it to be printed.
But no key is allowed to have more than seven sharps or flats, so in
most cases only one of the ways will result in a valid key, and the
other way will result in an error message.

The transpose and addtranspose parameters are allowed
in score and staff contexts, so they can
be set to different values on different staffs, and on the score as a whole.
This is useful for printing scores where some of the instruments are
transposing instruments (like B-flat clarinet).
You can set the transpose parameter on specific staffs to appropriate
values for the transposing instruments. Then if you decide you want to
move the entire score to a new key, you can set the addtranspose parameter
in score context.
You can enter all the music at true pitch, but print the score and/or
the individual parts with the correct transposition.

Another use for setting different transposition values is the following
trick, useful in guitar music for printing both the real chords and chords
for capo.
Say, for example, you have a song that is in B flat, but the guitar is
to use a capo on the third fret, and play in the key of G.
You could define the following macro to print both versions of a chord,
the capo version above the real version: